A personal firewall is an internet application that is used for controlling inbound and outbound traffic of a computer connected to a network or internet.

A personal firewall has the ability to deny or permit communication and transmission depending on a predefined policy of the personal firewall. A personal firewall is different from a conventional firewall because the personal firewall is designed and developed for the end users and protects a single computer or user from malicious programs, viruses, spywares and hacking attempts on the internet or a network.

Some firewalls control the traffic by prompting the user to take appropriate action, while others have predefined security policy which helps them white list or black list particular websites or nodes. A personal firewall is especially important for users with permanently  connected internet connection like cable net or DSL because such users have static IPs which make them more vulnerable.

A personal firewall also protects individual users against intrusions by providing intrusion detection services. The users is also notified by the personal firewall whenever an intrusion is attempted.

Common duties of a personal firewall are:

• A personal firewall informs you about intrusion attempts

• Personal firewall allows the user to control inbound and outbound traffic or their computer

• Personal firewall lets the user control the programs which can access the internet

• Personal firewall lets the user monitor programs performing inbound or outbound communications

• Personal firewall provides information about destination server.